Reactive oxygen species (ROS) are byproducts of the normal metabolism of living organisms. ROS include oxygen-derived free radicals and non-radical derivatives that can cause oxidative damage to biological structures. ROS have also been shown to play a role in the aging process and a number of pathological syndromes such as, for example, diabetes. However, oxidative damage caused by ROS can be reduced or prevented through a number of mechanisms such as, for example, the use of low molecular weight antioxidants that can react directly with ROS in the body.
Such low molecular weight antioxidants include lipoic acid, dihydrolipoic acid and other lipoic acid derivatives. Over the last several years these particular antioxidants have been intensively studied as potentially useful therapeutic agents. Results from model and clinical studies have demonstrated that both lipoic acid and dihydrolipoic acid (DHLA) are capable of scavenging ROS such as, for example, singlet oxygen, hypochlorous acid and the trichloromethylperoxyl radical, and hydroxyl radicals. In addition, both compounds may chelate redox-active transition metal ions such as, for example, copper and iron. Under normal circumstances, copper and iron are typically complexed with other proteins. But, under some conditions of trauma, such transition metals can be released and act as catalyzing agents in oxidative processes that can cause cellular damage.
Lipoic acid or alpha-lipoic acid (ALA), and DHLA are naturally synthesized by living organisms at a cellular level. Normally, DHLA is formed in the cells. Cells tend to absorb ALA, reduce it to DHLA and then secrete the DHLA into the blood stream. Once in the blood stream, DHLA can react with an oxidizing agent such as, for example, oxidized vitamin C thereby scavenging oxygen from and regenerating the vitamin C, and form ALA that can be reabsorbed by the cells. However, cells generally only produce an amount of DHLA sufficient for metabolic function. Additional or supplemental amounts of lipoic acid or DHLA must generally be derived from external sources such as dietary intake and/or nutritional supplements.
Until recently, naturally occurring DHLA could only be obtained indirectly through consuming ALA, which in turn, was converted by the body into small amounts of DHLA. However, this process does not deliver a significant or reliable supply of DHLA. Thus, ALA and DHLA for use in dietary supplements and medicaments have typically been derived from synthetic sources.
Several research studies show the benefits from the use of alpha-lipoic acid (ALA). Unfortunately, most of these research studies have used a synthetic form that contains equal amounts of the R- and the S-racemic forms of lipoic acid. The S-form occurs only in synthetic source ALA and has a negative, pro-inflammatory effect on body tissues. Thus, DHLA derived from such synthetic ALA exhibits both desirable antioxidant properties and undesirable pro-oxidant properties.
Thus, there is a need and a demand for a beneficial compound such as a stabilized dihydrolipoic acid (DHLA) compound that can be derived from a natural source. In particular, there is a need and a demand for a DHLA compound derived from a once-living source that is stable and, in long term use, capable of preventing and/or repairing oxidative damage to tissue, DNA and/or other important chemicals in the body such as, for example, vitamins C and E. There is a further need and a demand for a microbiological culture media and method for preparing a stabilized DHLA compound for use in a medicament or a nutritional supplement.